Hydroxypyridonemethide azo dyes

ABSTRACT

Hydroxypyridonemethide azo dyes conforming to the formula (I) or its tautomeric forms                    
     where X 1  to X 4 , R 1  and R 2  are each as defined in the description part, 
     are very useful for dyeing and printing hydrophobic synthetic fiber materials and their blends with natural fiber materials.

The invention relates to novel hydroxypyridonemethide azo dyes,processes for their preparation and their use and also dye mixturescontaining hydroxypyridonemethide azo dyes. EP-A 767 220 alreadydiscloses similar azo dyes. These dyes, however, are still in need ofimprovement with regard to their application properties, especiallytheir thermomigration fastness.

Novel hydroxypyridonemethide azo dyes have been found that,surprisingly, are notable for excellent thermomigration fastness andsublimation fastness coupled with good general fastnesses.

The present invention provides novel hydroxypyridonemethide azo dyesconforming to the formula (I) or its tautomeric forms

where

X¹ is H, Cl, Br, —CN, —CH═O, —CO—T, —CO₂—R², —SO₂—T, or —NO₂,

X², X³ and X⁴ are independently H, Cl or Br,

R¹ is H, T, or —CF₃, and

R² is straight-chain or branched C₁-C₄-alkyl,

where

T is straight-chain or branched C₁-C₁₀-alkyl which may be interrupted by1 or 2 oxygen atoms in ether function and/or substituted by one or more,preferably one, phenyl or hydroxyl radicals, or is phenyl which may besubstituted by 1 to 2 identical or different radicals selected from thegroup consisting of Cl, Br and C₁-C2-alkyl.

The dyes of the formula (I) can also exist in tautomeric forms, of whichthe most important is the formula (Ia)

For the purposes of the present invention, the formula (I) in itsgeneral and preferred meanings includes all possible tautomeric forms,especially that of the formula (Ia).

Preference is given to hydroxypyridonemethide azo dyes of the formula(I) or (Ia) where

X², X³ and X⁴ are each H.

Particular preference is given to dyes of the formulae (I) and (Ia),where

X², X³ and X⁴ are each H,

R¹ is H, —CH₃, —C₂H₅, —CH(CH₃)₂, unsubstituted phenyl or CF₃, and

R² is CH₃ or C₂H₅.

Very particular preference is given to dyes of the formula (I) where

x¹ is H, Cl, Br, or —NO₂,

X², X³ and X⁴ are each H,

R¹ is H, —CH₃, —C₂H₅, or —CH(CH₃)₂, and

R² is CH₃ or —C₂H₅.

Preference is given in particular to dyes of the formula (I) where

X¹ is nitro,

X², X³ and X⁴ are each H,

R¹ is H or CH₃, and

R² is CH₃ or C₂H₅.

The dyes of the invention may be prepared, for example, by diazotizingan amine of the formula (II)

where

X¹, X², X³ and X⁴ are each as defined above,

and coupling it onto a coupling component of the formula (III)

where

R¹ and R² are each as defined above and

E is a substituent that is displaceable by electrophilic substitution,preferably by H, —CO₂H, —CH₂OH, —SO₃H, —CH═O, —COT, —CONH₂, —CONHT,

and where T is as defined above.

Such a coupling process by displacement of a substituent is describedfor example in GB-A 2036 775 and JP-A 58 157 863.

The coupling reaction may be carried out in aqueous and nonaqueoussolvents. Nonaqueous solvents are alcohols such as methanol, ethanol,propanol, butanol, pentanol, etc., dipolar aprotic solvents such as DMF,DMSO, NMP and water-immiscible solvents such as toluene orchlorobenzene.

The coupling is preferably carried out in a stoichiometric ratio ofcoupling component and diazo component, although it may be advantageousand sensible, partly for economic reasons, to use the cheaper componentin an excess of up to 30%.

The coupling is generally effected at temperatures between −30 to 100°C., preference being given to temperatures of −10 to 30° C., andparticular preference to temperatures of −5 to 10C.

The coupling may be carried out in an acidic as well as an alkalinemedium. Preference is given to pH <10, particular preference to pH <7.0,very particular preference to pH <5.0.

The diazo components of the formula (II) are literature known and partlyalso, like the particularly preferred 3-nitro-4-aminophenol,commercially available.

The coupling components of the formula (III) are likewise known andtheir preparation is described for example in EP-A 767 220.

The dyes of the formula (I) according to the invention are useful assuch, mixed with each other or else mixed with other disperse dyes fordyeing and printing, including by the inkjet process, hydrophobicsynthetic fiber materials and their blends with natural fiber materials.

Useful hydrophobic synthetic materials include for example secondarycellulose acetate, cellulose triacetate, polyamides and particularlypolyesters, for example polyethylene glycol terephthalate. Examples ofuseful natural fiber materials are cotton, regenerated cellulose fibersand wool.

The dyes of the invention or mixtures thereof are also useful forcoloring and printing waxes, oils and plastics such as polymethacrylate,PVC, polystyrene or ABS.

They are also useful for textile and nontextile thermal transferprinting, for example by means of a thermal head.

The coloring, dyeing and printing conditions, which include dyeing insupercritical carbon dioxide, are known per se, cf. for example EP-A 827988, DE-A 3508 904 and EP-A 474 600.

The dyes of the invention or mixtures thereof can also be used fordyeing keratinic fibers, for example in hair dyeing or in the dyeing offurs.

The novel dyes of formula (I) or their mixtures are further very usefulfor producing color filters as described for example in EP-A-399 473.

Finally they are also useful as colorants for preparing toners forelectrophotography.

The dyes of the invention or the mixtures thereof dye polyester inorange to violet shades having excellent thermomigration fastness andsublimation fastness, high color strength and a bright hue.

Particularly good affinity and build-up is provided by mixtures of thedyes of formula (I) which contain two or more, preferably two to 4,different dyes of the formula (I). Preference is given to mixtures whichdiffer in the R¹ and/or R² substituents.

The present invention further provides dye mixtures containing at leastone dye of the formula (I) and also at least one further disperse dye.Useful disperse dyes are the disperse dyes listed in the Color Index,especially benzodifuranone dyes, and also the disperse dyes known fromEP-A 767 220.

Benzodifuranone dyes which are preferentially suitable as mixture dyesare derived from the formula (IV)

where

Y¹ and Y² are independently H, C₁-C₆-alkoxy, with or withoutC₁-C₄-alkoxycarbonyl, C₁-C₄-alkoxy-C₂-C₄-alkoxycarbonyl or furfurylsubstitution, —OC₂H₄—O—C₁-C₄-alkyl or —OC₂H₄—O—(C₂H₄O)₁₋₆—C₁-C₄-alkyl.

Of these, the following may be mentioned in particular:

(IVa) Y¹=OCH₂CH₂CH₃, Y²=H

(IVb)

 Y²═H

(IVc) Y¹=OCH₂CH₂CH₃, Y²=OCH₂CO₂C₂H₄OC₂H₅

(IVd) Y¹=H, Y²=OCH₂CO₂C₂H₄OC₂H₅

Preference is given to dye mixtures containing at least one dye of theformula (I) and at least one dye of the formula (IV).

Preference is further given to dye mixtures containing at least one dyeof the formula (I) and at least one disperse dye of the formula (V)

where

D is the radical of a carbo- or heterocyclic diazo component,

A¹ and A² are independently H or a typical pyridone substituent,

A⁵ is H, a radical of the formula T, —OT¹, —NH₂, —NHT, —NT₂, —NHCOH,—NHCOT, —N═CH—T,—N═CT₂ or —NHSO₂T,

or

A¹ and A² and/or

A² and A³ and/or

A⁴ and A⁵ combine with the atoms in between in each case to form anunsaturated, substituted or unsubstituted 5- or 6-membered carbo- orheterocycle, with the proviso that in the event of ring formation byparticipation of one of A³ and A⁴ the nonparticipant radical is anelectron-attracting radical,

X is O, NH, NT, NCOT, NCO₂T or NSO₂T,

A³ and A⁴ are independently —CN, —CO₂T, —CONH₂, —CONHT, —CONT₂, CF₃,—CHO, —COT, —SO₂T, —SO3T⁴, —SO₃T⁵, SO₂NH₂, SO₂NHT, SO₂NT₂, —SOT, —CH═NH,—CH═NT, —CT═NH, —CT═NT,

 —CO—CO₂T, —NO₂, —NO, or T⁴ T⁵

but A³ and A⁴ are preferably not both T⁴ and/or T⁵

or

A³ and A⁴ combine with the carbon atom to which they are attached toform a cyclic active-methylene compound of the formula (VIa) to (VIv),these radicals being specified in the form of

where

V¹ is H or a substituent, especially Cl, Br, CH₃, —CO₂T¹, —CN, —NO₂,—CF₃ or —SO₂T¹, and

where

T is T¹ to T⁵, where

T¹ is alkyl, cycloalkyl or aralkyl,

T² is alkenyl,

T³ is alkynyl,

T⁴ is aryl and

T⁵ is hetaryl.

In particularly preferred disperse dyes of the formula (V)

A¹ is H, T¹, T⁴ or —CF₃,

A² is H, —CN, —CO₂T¹, —CONHT¹ or —CF₃,

A³ and A⁴ are independently —CN, —CO₂T¹, —CONHT¹, —CF₃, —CHO, —COT,—SO₂T, —NO², —T⁴ or —T⁵, subject to the proviso that

A³ and A⁴ are not both T⁴ or T⁵,

A⁵ is H, T¹, T², T⁴,

D is a radical of the formula

where

R¹¹ and R⁵¹ are independently H, CF₃, Cl, Br, —CN, —NO₂, —CO₂T¹, T¹, T⁵,—SO₂T¹, —SO₂T⁴,—OT¹, —OT², —OT⁴, —OCOT⁴, —OCOT⁴, —OSO₂T¹ or —OSO₂T⁴,

R²¹ and R⁴¹ are independently H, Cl, Br, —NO₂, —CF₃, T¹, —OT¹, —OT²,—OT⁴, —OCOT¹, —OCOT⁴, —OSO₂T¹ or —OSO₂T⁴,

R³¹ is H, Cl, Br, —CN, —NO₂, —CF₃, —CO₂T¹, T¹, T⁵, —OT¹, —OT², —OT⁴,—OCOT¹, —OCOT⁴, —SO₃T¹ or —SO₂T⁴,

T¹ is C₁-C₈-alkyl which may be substituted by C₁-C₈-alkoxy,—C₁-C₈-alkoxy-C₂-C₅-alkoxy, —OCOT¹, —CO₂T¹, Cl, Br, —CN or T⁴,

T² is C₂-C₈-alkenyl which may be substituted by —C₁-C₈-alkoxy,—C₁-C₈-alkoxy-C₂-C₅-alkoxy, —CN, —CO₂T¹, Cl or Br,

T⁴ is phenyl which may be substituted by Cl, Br, T¹, OT¹, —CF₃, —NO₂,—CNor —CO₂T¹,

T⁵ is oxazole, phenyloxazole, benzoxazole, thiazole, benzothiazole,thiadiazole or thiophene, which may be substituted by Cl, Br, T¹, —NO₂and/or —CO₂T¹, and

X is O.

In very particularly preferred disperse dyes of the formula (V)

A¹ is H or T¹,

A² is H, —CN or —CO₂T¹,

A³ is —CN or —CO₂T¹,

A⁴ is A³,

A⁵ is H or T¹,

D is a radical of the formula

where

R¹¹ and R⁵¹ are independently H, Cl, Br, —CN, —NO₂, —CO₂T¹, T¹, —OT¹ or—OT⁴,

R²¹ and R⁴¹ are independently H, Cl, Br, —NO₂, T¹ or —OT¹,

R³¹ is H, Cl, Br, —CN, —NO₂, T¹, —CO₂T¹ or —OT¹,

T¹ is C₁-C₆-alkyl,

T⁴ is phenyl which may be substituted by Cl, Br, —NO₂ and/or —CO₂T¹ and

X is O.

Preference is likewise given to dye mixtures containing at least one dyeof the formula (I), at least one dye of the formula (IV) and at leastone dye of the formula (V).

The dyes and dye mixtures of the invention may be converted into solidor liquid preparations by grinding, for example in a bead mill, in thepresence of assistants such as for example dispersants, wetting agentsand dustproofers.

EXAMPLE 1

A mixture of 7.3 ml of 50% of sulfuric acid and 9.0 ml of 96% ofsulfuric acid was gradually admixed with 9.1 g of 4-amino-3-nitrophenolat 0° C. 11 ml of 40% of nitrosylsulfuric acid were added dropwise at 0°C. After 4 hours of reaction at 0° C., the diazotization solution wasadded dropwise to an alkaline solution of 10.0 g of6-hydroxy-1-methyl-2-(1H)-pyridinylidenepropanedinitrile and 2 g of ureain 300 ml of water. A little ice was added to maintain the temperatureat 0-5° C. Sodium acetate was used to adjust the batch to pH 2. Thebatch was stirred overnight and filtered with suction, the filterresidue was washed with water, and drying of the press cake afforded 10g of the dye of the formula

which may be further purified by recrystallization from DMF.

λ_(max)=517 nm (CH₂Cl₂)

The dye dyes polyester in a bright red having excellent fastnessesespecially wetfastnesses and sublimation fastness.

Analogous or similar methods may be used to obtain the following dyeswhich likewise dye polyester with good fastnesses:

Hue on Ex. λ_(max.) poly- No. X¹ X² X³ X⁴ R¹ R² (nm) ester 2 —NO₂ H H HH C₂H₅ 517(CH₂Cl₂) red 3 —NO₂ H H H CH₃ CH₃ 517(DMF) red 4 —NO₂ H H HCH₃ C₂H₅ 517(DMF) red 5 —CO₂CH₃ H H H H CH₃ 504(CH₂Cl₂) red 6 H Cl Cl HH CH₃ 496(CH₂Cl₂) scarlet 7 H H H H H CH₃ 508(CH₂Cl₂) red 8 Br H H H HCH₃ 505(CH₂Cl₂) red

EXAMPLE 9

Bead milling and subsequent spray drying is used to prepare a dyeingproduct from 10 parts of the dye of Example 1, 10 parts of the dye ofExample 2, 10 parts of the dye of the formula

63 pars of standardizer based on a dispersant (commercially availableligninsulfonate: condensation products of formaldehyde, naphthalene andsulfuric acid), commercially available wetting agents (alkoxylatedalkylphenols), commerically available dustproofers (mineral oil withemulsifiers) and 7 parts of residual moisture.

In a dye bath set to a pH of 4.5 with sodium phosphate and acetic acid,100 parts of a polyester fabric (polyethylene terephthalate) are dyedwith 0.9 g of the above-described dyeing product at a liquor ratio of10:1 to 40:1 at 125 to 135° C. for 30 to 45 minutes.

This provides bright red dyeings having good fastnesses, especially goodaffinity and excellent thermomigration fastness.

EXAMPLE 10

Bead milling and subsequent spray drying is used to prepare a dyeingproduct from

18.8 parts of the dye of Example 4,

12.5 parts of the dye of Example 3,

62.6 parts of standardizer based on commercially availableligninsulfonates, commercially available dispersants (condensationproducts of formaldehyde, naphthalene and sulfuric acid), commerciallyavailable wetting agents (alkoxylated alkylphenols), commerciallyavailable dustproofers (mineral oil with emulsifiers) and

6.1 parts of residual moisture.

In a dye bath set to a pH of 4.5 with sodium phosphate and acetic acid,100 parts of a polyester fabric (polyethylene terephthalate) are dyedwith 0.75 g of the above-described dyeing product at a liquor ratio of10:1 to 40:1 at 125 to 135° C. for 30 to 45 minutes.

This provides bright red dyeings having good fastnesses, especiallygood, affinity and excellent thermomigration fastness.

What is claimed is:
 1. A hydroxypyridonemethide azo dye conforming tothe formula (I) and its tautomeric forms

where X¹is H, Cl, Br, —CN, —CH═O, —CO—T, —CO₂—R², —SO₂—T, or —NO₂, X²,X³ and X⁴ are independently H, Cl or Br, R¹ is H, T, or —CF₃, and R² isstraight-chain or branched C₁-C₄-alkyl, where T is straight-chain orbranched C₁-C₁₀-alkyl which may be interrupted by 1 or 2 oxygen atoms inether function and/or substituted by one or more phenyl or hydroxylradicals, or is phenyl which may be substituted by 1 to 2 radicalsselected from the group consisting of Cl, Br and C₁-C₂-alkyl.
 2. A dyeas claimed in claim 1, wherein X², X³ and X⁴ are each H.
 3. The dye asclaimed in claim 1, wherein X², X³ and X⁴ are each H, R¹ is H, —CH₃,—C₂H₅, —CH(CH₃)₂, unsubstituted phenyl or CF₃, and R² is CH₃ or C₂H₅. 4.The dye as claimed in claim 2, wherein X², X³ and X⁴ are each H, R¹ isH, —CH₃, —C₂H₅, —CH(CH₃)₂, unsubstituted phenyl or CF₃, and R² is CH₃ orC₂H₅.
 5. The dye as claimed in claim 1, wherein X¹ is H, Cl, Br, or—NO₂, X², X³ and X⁴ are each H, R¹ is H, —CH₃, —C₂H₅, or —CH(CH₃)₂, andR² is CH₃ or —C₂H₅.
 6. The dye as claimed in claim 4, wherein X¹ is H,Cl, Br, or —NO₂, R¹ is H, —CH₃, —C₂H₅, or —CH(CH₃)₂.
 7. A dye as claimedin claim 1, wherein X¹ is nitro, X², X³ and X⁴ are each H, R¹ is H orCH₃, and R² is CH₃ or —C₂H₅.
 8. A dye as claimed in claim 6, wherein X¹is nitro, R¹ is H or CH₃.
 9. A process for preparing the aye of claim 1,which comprises diazotizing an amine of the formula (II)

where X¹, X², X³ and X⁴ are each as defined in claim 1, and coupling itonto a coupling component of the formula (III)

where R¹ and R² are each as defined in claim 1 and E is a substituentthat is displaceable by electrophilic substitution.
 10. A dye mixturecontaining at least two different dyes of the formula (I) as claimed inclaim
 1. 11. A dye mixture as claimed in claim 10, wherein the dyes ofthe formula (I) differ with regard to R¹ and/or R², R¹ being H or CH₃and R² being CH₃ or C₂H₅.
 12. A dye mixture containing at least one dyeof the formula (I) as claimed in claim 1 and at least one disperse dyethat differs from the formula (I).
 13. A dye mixture comprising at leastone dye of the formula (I) as claimed in claim 1, at least one dye ofthe formula (IV) or formula (V) or mixture of formulas (IV) and (V)

wherein Y¹ and Y² are independently H, C_(l)-C₆-alkoxy, with or withoutC₁-C₄-alkoxy-carbonyl, C₁-C₄-alkoxy-C₂-C₄-alkoxycarbonyl or furfurylsubstitution, —OC₂H₄—O—C₁-C₄-alkyl,or —OC₂H₄—O—(C₂H₄_(O))₁₋₆—C₁H₄-alkyl,

wherein D is the radical of a carbo- or heterocyclic diazo component, A¹and A² are independently H or a pyridine substituent, A⁵ is H, a radicalof the formula T, —OT¹, —NH₂, —NHT, —NT₂, —NHCOH, —NHCOT,—N═CH—T, N═CT₂or NHSO₂T, or A¹ and A² and/or A² and A³ and/or A⁴ and A⁵ combine withthe atoms in between in each case to form an unsaturated, substituted orunsubstituted 5- or 6-membered carbo- or heterocycle, with the provisothat in the event of ring formation by participation of one of A³ and A⁴the nonparticipant radical is an electron-attracting radical, X is O,NH, NT, NCOT, NCO₂T or NSO₂T, A³ and A⁴ are independently —CN, —CO₂T,—CONH₂, —CONHT, —CONT₂, CF₃, —CHO, —COT, —SO₂T, —SO₃T⁴, —SO₃T⁵, SO₂NH₂,SO₂NHT, SO₂NT₂,—SOT, —CH═NH, —CH═NT, —CT═NH, —CT═NT,

 —CO—CO₂T, —NO₂, —NO, or T⁴ T⁵ but A³ and A⁴ are not both T⁴ and/or T⁵or A³ and A⁴ combine with the carbon atom to which they are attached toform a cyclic active-methylene compound of the formula (VIa) to (VIv),these radicals being specified in the form of

wherein V¹ is H or a substituent, wherein said substituent is Cl, Br,CH₃, —CO₂T¹, —CN, —NO₂, —CF₃ or SO₂T; and herein T is T¹ to T⁵, where T¹is alkyl, cycloalkyl or aralkyl, T² is alkenyl, T³ is alkynyl, T⁴ isaryl and T⁵ is hetaryl.
 14. A process for dying a hydrophobic syntheticfiber material or blends of hydrophobic synthetic fiber materials with anatural fiber material which comprises contacting the synthetic materialwith the dye as claimed in claim
 1. 15. A process for dying ahydrophobic synthetic fiber material or blends of hydrophobic syntheticfiber materials with a natural fiber material which comprises contactingthe synthetic material with the dye mixture as claimed in claim
 10. 16.The process as claimed in claim 14, wherein the hydrophobic syntheticfiber materials are secondary cellulose acetate, cellulose triacetate,polyamides or polyesters and the natural fiber materials are cotton,regenerated cellulose fibers or wool.
 17. The process as claimed inclaim 15, wherein the hydrophobic synthetic fiber materials aresecondary cellulose acetate, cellulose triacetate, polyamides orpolyesters and the natural fiber materials are cotton, regeneratedcellulose fibers or wool.
 18. A dyed hydrophobic synthetic material dyedwith the dye as claimed in claim
 1. 19. A dyed hydrophobic syntheticmaterial dyed with the dye mixture as claimed in claim 10.